"Empty room" is a confusing name in the room list as the rooms are not necessarily empty

### Steps to reproduce

1. Scroll down the room list
2. Observe rooms called "empty room"
3. Click on it

### Outcome

#### What did you expect?
See nothing, as it is supposedly empty

#### What happened instead?
See lots of content

It's like someone moving out of a flat share leaving all their stuff behind. That's hardly an empty room then. The metaphor doesn't work here.

Other apps like Telegram or Signal call this "deleted account". That works better as the room bake for DMs is typically the name of the account holder and if that person is gone, it's a deleted account but not an empty conversation.

On Matrix, the amount holder might not have left though, so deleted account doesn't work. Inside the room, the MXID is still visible, so why not use that? After all that's the former counterparty of the conversation.

### Your phone model

_No response_

### Operating system version

_No response_

### Application version and app store

_No response_

### Homeserver

_No response_

### Will you send logs?

No

### Are you willing to provide a PR?

No

The issue names no files, tests, or entry points, so begin by finding the room-list label used for rooms whose counterpart has left. Check the wording against the stated Matrix constraint that the MXID remains visible, and consider the work done when the misleading “empty room” label is replaced without changing the room’s content.

Written by the indexing model from the issue text.